scholarly journals Reproductive Ecology of Male and Female Strobili and Mating System in Two Different Populations ofPinus roxburghii

2012 ◽  
Vol 2012 ◽  
pp. 1-13 ◽  
Author(s):  
Chandra Mohan Sharma ◽  
Vinod Prasad Khanduri ◽  
Sunil Kumar Ghildiyal
Keyword(s):  
Mating System ◽  
Natural Populations ◽  
Production Capacity ◽  
Pollen Grains ◽  
Seed Orchard ◽  
Reproductive Period ◽  
Female Cone ◽  
Lower Altitude ◽  
Female Ratio ◽  
Male And Female

We studied several flowering traits, namely, male-female cone phenology, male-female cone production per tree, mating system, sex ratio, air-borne pollen grains and pollen migration, over four successive years in two different natural populations ofP. roxburghiifrom Garhwal Himalaya, India. Assessment of each trait mentioned except pollen dispersion was done by selecting five representative trees randomly in each population. The pollen migration was studied on naturally isolated source trees. The pollen trapping was done in all directions up to 2.5 km. The average reproductive period inP. roxburghiiwas 36 days with 3–5 days protandry. There were significant year and population effects for male and female cone output and pollen grains production per tree. In mass production year (1999), an average production of pollen cone per tree was estimated as42.44±8.32×103at lower altitude and28.1±0.89×103at higher altitude. The controlled pollination results in high level of outcrossing with 90% seed setting. We conclude that the high male-female ratio and tremendous pollen production capacity inP. roxburghiiindicate high male competition among trees within populations. The isolation strip of 600 m is considered minimal for the management of seed orchard.

scholarly journals Studies on the Pollination Characteristics and Pollination Level of Chinese fir Seed Orchard

2004 ◽  
Vol 53 (1-6) ◽  
pp. 7-11 ◽  
Author(s):  
Z. Zhuowen
Keyword(s):  
Accumulation Rate ◽  
Pollen Grains ◽  
Seed Orchard ◽  
Distribution Patterns ◽  
Chinese Fir ◽  
Female Cone ◽  
Bottom Part ◽  
Male And Female ◽  
Seed Orchards ◽  
Male Cone

Abstract Data from three seed orchards (Chongyang, Zhangle and Laoshan) and Lintian forest were used to study pollination characteristics, pollination level, pollen and ovule production in Chinese fir. The results show that male and female cones have their own distribution patterns within crowns. Male cones are located in the middle to top and female cones the middle to bottom part of the crown. Because of lower density of trees in seed orchard than that in a stand, female cones are distributed over the entire crown in seed orchard trees. Chinese fir male and female cones appear to be very well adapted for wind as the pollination mechanism. There is no difference in the number of pollen grains produced by one pollen sac among trees in the same clone, but there are differences between clones. There are differences between both clones and years in female cone number, male cone number and their ratio. The pollen accumulation rate during pollination should be 3 to 5 pollen grains/mm2 to ensure fertilization. The Chinese fir seed orchards in this study produced too much pollen and could be improved by stimulation of more female flowers in order to produce more seeds.

Mating system variation among individual ramets in a Douglas-fir seed orchard

1990 ◽  
Vol 20 (10) ◽  
pp. 1672-1675 ◽  
Author(s):  
V. J. Erickson ◽  
W. T. Adams
Keyword(s):  
Mating System ◽  
Seed Orchard ◽  
Floral Biology ◽  
Douglas Fir ◽  
Pollen Production ◽  
Male And Female ◽  
Floral Phenology ◽  
Female Flowering ◽  
High Degree

Proportions of outcrossed progeny (ti) in five ramets of five clones with variable floral phenology and pollen production were investigated in a Douglas-fir (Pseudotsugamenziesii var. menziesii (Mirb.) Franco) seed orchard. Estimates of ti[Formula: see text] were significantly heterogeneous among the five ramets, ranging in value from 0.50 to 1.07. Variation in [Formula: see text] corresponded well with variation among ramets in floral biology. Ramets that flowered much earlier than other individuals in the orchard and (or) had a high degree of synchrony in timing of male and female flowering produced the lowest [Formula: see text].

scholarly journals High Levels of Outcrossing in a Family Trial of Western Australian Sandalwood (Santalum spicatum)

2007 ◽  
Vol 56 (1-6) ◽  
pp. 222-230 ◽  
Author(s):  
K. Muir ◽  
M. Byrne ◽  
E. Barbour ◽  
M. C. Cox ◽  
J. E. D. Fox
Keyword(s):  
Genetic Diversity ◽  
Mating System ◽  
Natural Populations ◽  
Seed Orchard ◽  
Seed Crop ◽  
The Mean ◽  
Santalum Spicatum ◽  
High Level ◽  
Western Australian ◽  
Seed Collections

Abstract The mating system of Western Australian sandalwood (Santalum spicatum) was investigated in seed collections from a family trial. The mean outcrossing rate was high (95.2%) although there was variation among families and one family showed particularly low outcrossing, high bi-parental inbreeding and high correlated paternity. Variation in flowering time between this family and others in the trial was the most likely cause of the high inbreeding and low number of fathers contributing to the seed crop in trees from this family. The high level of outcrossing in the rest of the families indicated that S. spicatum has a preferentially outcrossed mating system, but that it is capable of selfing when conditions are unsuitable for outcrossing. The seedling progeny showed no influence of inbreeding on seedling height at 4 months. Analysis of genetic diversity revealed high levels of genetic diversity have been captured in the seed crop from the trial, and this diversity is comparable to that identified in a previous study of natural populations from throughout the range of the species. These results indicated that production of seed through seed orchards will be a successful means of deployment of breeding gains in the species, however it is essential to ensure overlap in flowering times among different families planted in a seed orchard.

Effect of applied growth regulators on cone production in Douglas-fir, and relation of endogenous growth regulators to cone production capacity

1980 ◽  
Vol 10 (3) ◽  
pp. 405-414 ◽  
Author(s):  
E. E. McMullan
Keyword(s):  
Abscisic Acid ◽  
Growth Regulators ◽  
Growth Regulator ◽  
Production Capacity ◽  
Seed Orchard ◽  
Douglas Fir ◽  
Female Cone ◽  
Cone Production ◽  
Male Cone ◽  
Stage Of Development

Extracts of buds and young shoots of a good cone-producing clone of Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco) were tested for cone production effect on seed orchard Douglas-fir trees chosen for their history of poor cone production. Other metabolites, including gibberellin 4/7, arginine, and abscisic acid were also tested. Growth regulator levels in good and poor cone-producing clones of Douglas-fir were compared over the period of bud break and shoot elongation.No evidence was obtained for the presence of growth regulators critical to cone production in purified extracts from ramets of the good cone-producing clone. Applied gibberellin 4/7 increased male and female cone production. Crude extracts of a good cone-producing clone increased male cone bud production. Arginine and abscisic acid had no effect.Bioassays indicated that growth regulator levels in buds and young shoots changed greatly with stage of development but were similar in good and poor cone-producing clones.

The mating system in natural populations of western redcedar (Thuja plicata)

2001 ◽  
Vol 79 (6) ◽  
pp. 753-756 ◽  
Author(s):  
Lisa M O'Connell ◽  
Frédérique Viard ◽  
John Russell ◽  
Kermit Ritland
Keyword(s):  
British Columbia ◽  
Mating System ◽  
Natural Populations ◽  
Seed Orchard ◽  
Outcrossing Rate ◽  
Thuja Plicata ◽  
Western Redcedar ◽  
Outcrossing Rates ◽  
Glucose 6 Phosphate Dehydrogenase ◽  
Thuja Plicata Donn

Outcrossing rates and the correlation of paternity were estimated in six natural populations of western redcedar (Thuja plicata Donn. ex D. Don) in southwestern British Columbia. Over 3000 offspring were assayed, as progeny arrays, for the only sufficiently polymorphic isozyme locus in this species, glucose-6-phosphate dehydrogenase. Estimates of population outcrossing rates ranged from 0.173 to 1.257 and averaged 0.715 ± 0.045 (mean ± SD). Estimates of the correlation of paternity generally did not differ from zero. Six of the seven outcrossing estimates (one population was surveyed in two consecutive years) were higher than a previous seed orchard study. However, these outcrossing rates are still lower than those estimated for most other species of conifers. Population outcrossing rates also showed wide variation, and this variation is discussed in terms of ecological and phenological differences among populations.Key words: Cupressaceae, conifers, isozymes, outcrossing rate, inbreeding.

scholarly journals Individual growth of Heleobia piscium in natural populations (Gastropoda: Cochliopidae) from the multiple use natural Reserve Isla Martin Garcia, Buenos Aires, Argentina

2008 ◽  
Vol 68 (3) ◽  
pp. 617-621 ◽  
Author(s):  
SM. Martin
Keyword(s):  
Buenos Aires ◽  
Natural Populations ◽  
Dynamic Structure ◽  
Reproductive Period ◽  
Individual Growth ◽  
Growth Equation ◽  
Multiple Use ◽  
Natural Reserve ◽  
Drainage Channels ◽  
The Individual

The present work analyses the individual growth of Heleobia piscium in natural conditions in coastal drainage channels of the Multiple Use Natural Reserve Isla Martín García, Buenos Aires, Argentina. Isla Martín García is located in the Upper Río de la Plata, to the south of the mouth of the Uruguay river (34° 11' 25" S and 58° 15' 38" W). Monthly collections were made from July 2005 to July 2006 in the eastern part of the island (Arena Beach). The population of H. piscium showed a complex and dynamic structure of sizes during a long period of the annual cycle. Two cohorts could be detected. The Bertalanffy growth equation was: Lt = 6 (1-e -1.85 (t+0.38)) and Lt = 3.9 (1-e -0.19 (t+4.84)) for cohorts 1 and 2, respectively. The pattern of population growth displayed a staggered model, where the greatest growth is observed during the summer. The reproductive period occurred during six months, from the beginning of summer to middle of fall. Based on only one reproductive effort, this pattern is not similar to that of other cogeneric species already studied.

scholarly journals Effects of herbivory and its timing on reproductive success of a tropical deciduous tree

2020 ◽  
Vol 126 (5) ◽  
pp. 957-969
Author(s):  
Enya N Quiroz-Pacheco ◽  
Francisco Mora ◽  
Karina Boege ◽  
César A Domínguez ◽  
Ek del-Val
Keyword(s):  
Reproductive Success ◽  
Structural Equation ◽  
Structural Equation Models ◽  
Pollen Grains ◽  
Leaf Damage ◽  
Deciduous Tree ◽  
Herbivore Damage ◽  
Male And Female ◽  
Foliar Damage ◽  
The Impact

Abstract Background and Aims The implications of herbivory for plant reproduction have been widely studied; however, the relationship of defoliation and reproductive success is not linear, as there are many interacting factors that may influence reproductive responses to herbivore damage. In this study we aimed to disentangle how the timing of foliar damage impacts both male and female components of fitness, and to assess when it has greater impacts on plant reproductive success. Methods We measured herbivore damage and its effects on floral production, male and female floral attributes as well as fruit yield in three different phenological phases of Casearia nitida (Salicaceae) over the course of two consecutive years. Then we tested two models of multiple causal links among herbivory and reproductive success using piecewise structural equation models. Key Results The effects of leaf damage differed between reproductive seasons and between male and female components of fitness. Moreover, the impact of herbivory extended beyond the year when it was exerted. The previous season’s cumulated foliar damage had the largest impact on reproductive characters, in particular a negative effect on the numbers of inflorescences, flowers and pollen grains, indirectly affecting the numbers of infructescences and fruits, and a positive one on the amount of foliar damage during flowering. Conclusions For perennial and proleptic species, the dynamics of resource acquisition and allocation patterns for reproduction promote and extend the effects of herbivore damage to longer periods than a single reproductive event and growing season, through the interactions among different components of female and male fitness.

scholarly journals Hyperparasitism in caves: bats, bat flies and ectoparasitic fungus

2018 ◽  
Vol 1 ◽  
Author(s):  
Katrine Jensen ◽  
Luísa Rodrigues ◽  
Thomas Pape ◽  
Anders Garm ◽  
Sergi Santamaria ◽  
...  
Keyword(s):  
Soft Tissues ◽  
Natural Populations ◽  
Common Species ◽  
Unique Case ◽  
Male And Female ◽  
Entire Life ◽  
Bat Flies ◽  
Starting Point ◽  
Bat Fly ◽  
Peculiar Case

Bat flies (Nycteribiidae) of the order Diptera are highly specialized bloodsucking ectoparasites living on bats. The life-cycle of the bat flies emphasizes their obligate relationship with their hosts as they spend almost their entire life on bats. Upon mating, the female bat fly carries the larvae internally until the 3rd-instar when it deposits the larvae on the ceiling of the roost occupied by bats. The larvae then form a puparium. After 3-4 weeks the adult bat fly emerges from the puparium and starts searching for a host bat to colonize. Some of these ectoparasitic bat flies themselves are infected with an ectoparasitic fungus of the genus Arthrorhynchus (Laboulbeniales). Ascospores of the fungi attach themselves to the cuticle of the bat fly and develop a very conspicuous haustorium that penetrates into the soft tissues from where it presumably extract nutrition from the hemolymph of the bat flies. This interaction converts the fungus into a hyperparasite. Both the parasite and hyperparasite are obligates and cannot live separate from their hosts. This peculiar case of hyperparasitism remains highly unknown. The bat flies were collected in caves of Portugal, in maternity and hibernation bat seasons, and in the autumn migration period. The most common species of cave-dwelling bat species in Portugal is Miniopterus schreibersii, frequently parasitized with Nycteribia schmidlii and Penicillidia conspicua bat flies. We have studied the prevalence of the Laboulbeniales of the genus Arthrorhynchus in natural populations of bat flies. The site and position of the fungus on male and female bat flies unveils the mechanism of fungal transmission among bat flies, indicating that it occurs during mating behavior. This study is the starting point towards the understanding of this unique case of fungus-insect-vertebrate hyperparasitism interaction. See Suppl. material 1.

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